Sewing machine



A. AUSTLID 2,579,248

SEWING MACHINE Filed Jn. 18, 1947 Dec. 18, 1951 Patented Dec. 18, 1951SEWING MACHINE Arnljot Austlid, Oslo, Norway Application January 18,1947, Serial No. 722,814 In Norway `llanuary 22, 1946 Claims.

This invention relates to sewing machines adapted for makingzig-zag-seams.

The machine in question is of the type in which the needle bar and thelooper shaft thereof are interconnected by a displaceable bail or thelike adapted to be reciprocated in the longitudinal direction of themachine, thus transferring the same movements to the needle bar and tothe looper shaft, whereby zigzag-seams may be made.

It is an object of the invention to provide for such interconnection ofthe needle bar, the ball and the looper shaft that said bar and shaftwill be displaced absolutely in unison in the 1ongitudinal direction ofthe machine.

Another object is to provide a simple but effective driving arrangementfor said bail, which arrangement is adjustable in a simple manner, so asto set the bail for zigzag-seams of different widths or for usualstraight seam if desired.

Other features of the invention are disclosed in and by the followingdescription.

The annexed drawing illustrates an embodiment of the invention, whereonly those parts of the machine which relate to the invention are shown.

Figure 1 is a side View of a sewing machine according to the invention,part of the front being broken away, to show certain features of themechanism.

Figure 2 is an end view of the same, also with a part broken away.

Figure 3 shows, on a larger scale, a detail of the mechanism.

The sewing machine body consists of the arm I with head and supportingstandard, and of the base plate 2 of channel-formed section. Withinthebase plate is journalled a looper shaft d, driven by a motor or in othersuitable manner, and carrying a looper 5, which is located beneath theneedle bar 3 and 4cooperates with the needle. When the machine is to beused for sewing zigzag-seams the needle bar 3 and the looper shaft 4with its looper 5 must reciprocate synchronously in the longitudinaldirection of the machine, and the needle must be moved down into thefabric each time the needle bar and the looper are at one of the endpositions of their reciprocating movements.

Intercoupling of needle bar and looper shaft is obtained by means of abail E-, reciprocally housed in the machine arm i. At one end of saidbail is directly journalled the needle bar 3, and the other end of thebail directly carries the looper shaft 5, which is rotatable but notdisplaceable therein. More specifically, the bail 6 has an enlarged endportion 6 in which the needle bar 3 is slidably mounted for verticalmovement. The drive means for reciprocating the needle bar vertically isomitted as superfluous, being understood in the art, and forming noactual part of the invention. On the other hand, the downwardlyprojecting portion 6" of bail 6 may be provided with a hole in whichlooper shaft 4 is rotatably mounted, thus the bail and looper shaft aremovably connected together and associated. In order to prevent undesiredaxial movement of this looper shaft relatively to the bail, the bailportion 5" is located between two shoulders or flanges 2S fixed on thelooper shaft. Thus, when the bail 6 is reciprocated in the longitudinaldirection of the machine, the needle bar and the looper shaft both mustmove exactly in the same manner.

The bail 6 receives its reciprocating movement from a crank 8 on a shaftI rotated by the machines driving mechanism. The latter includes thegear 25 which meshes with and is driven by pinion 2t on the end oflooper shaft 4. The length of pinion 2S is, of course selected to besufficient to allow the pinion to slide along in parallelism to the axisof gear 25 during longitudinal displacement of looper shaft 4. In orderto facilitate axial movement of the looper shaft, the rotor of thedriving motor 21 is axially movable a short distance corresponding tothe eX- tent of the axial movement of the mentioned looper shaft whichis secured to the rotor. 'I'he connecting rod 9 of the crank ispivotally attached to an arm II, between the ends thereof. by means of apin I0. At one end thereof said arm Il is by means of a pin I2 pivotedon the vertical part of the bail 6, and the other end of arm II carriesa follower roller I3, engaged in a cam groove I4 provided in a guidemember I5', which for instance may be cylindrical. This guide member I5is secured to a shaft I5, which may be adjusted into different angularpositions by means of an arm I1, whereby the groove I4 may be set indifferent angular positions.

The arrangement described operates as follows: When the crank 8 rotatesthe follower roller I3 is displaced in and guided by the cam groove I4,and if the latter is set in an oblique or sloping position, for instanceas shown in Figure 1, roller I3 must reciprocate a little in horizontaldirection, arm I I simultaneously being raised and lowered, swinging onits pivot I2. This reciprocating movement of roller I3 is, through arm II and pivot I2, transferred to the bail 6, which latter thereby causesthe needle bar and the looper shaft to reciprocate accordingly. Byturning shaft IS by means of arm II the guide member I5 with groove I4may be set in any desired angular position, thus adjusting the extent ofthe reciprocating movement and thereby the width of the zigzag-seam.When groove I4 is set in vertical position no reciprocating movement ofbail 6 occurs, and the machine will sew an ordinary, straight seam. Inorder that no movement at all shall be imparted to bail 6- when thegroove is in this position, the major intermediate portion of the grooveis formed with a circular curve having its center of curvature in theaxis of pivot I2, the roller I3 then exerting no pressure on the wallsof the groove when arm I I is raised and lowered.

In order to enable the seam to be shifted to the right or to the leftwithout shifting the piece of fabric, shaft IG is eccentricallyjournalled in a sleeve I8, which latter is rotatably supported in thefront material of the machine body and adapted to be set in differentangular positions by means of an arm ZIJ. Turning of sleeve I 8 causesshifting of shaft I6 and thus also of guide member I5 towards the leftor towards the right, and such shifting is, through arm I'I and bail 6,transferred to the needle bar and to the looper shaft.

Figure 3 shows a section through the guide member I5 with groove I4 andthe roller I3, on a larger scale.

The fabric mover or feeder 2I is driven from a shaft 22. Said shaftcarries two eccentric portions 23 and 24 respectively, which are coupledto the fabric mover by means of arms, so

that the fabric mover receives a vertical and also a horizontalreciprocating movement. Control of the stitch-length and also reversionof the direction of movement of the fabric is effected by means of acontrolling arm, in a manner known per se. However, in accordance withthe invention said control mechanism is so arranged, that the fabricmover is automatically lowered if the stitch-length is adjusted tobecome zero, and is again raised if the stitch-length is increased.

Preferably the looper shaft 4 is provided with an extension 28penetrating the material of the machine body and adapted for attachmentof a pool member when thread should be spooled.

The constructional details of the arrangement shown may be widelymodined and varied within the scope of the invention.

I claim:

l. In a zig-zag stitch forming sewing machine comprising a base; amachine body on said base; and a horizontal looper shaft mounted in saidbase for recipr-ocation in a horizontal direction, the combination ofa'needle bar arranged partly within the machine body and dependingtoward said base; an elongated bail located within said machine bodyhaving an integral depending portion projecting into said base andmounted for horizontal reciprocation; an enlarged end portion upon theelongated bail in which the needle bar is slidably mounted for verticalmovement, the depending portion of said bail having a bearing hole forsupporting said looper shaft in order to allow the latter to extendthrough said bail; means upon said looper shaft engaging with said bailat both ends of the bearing hole therein for preventing axialdisplacement of said looper shaft with respect to said bail; andoperating means for reciprocating said bail in the horizontal directionand thereby oscillating the bail together with said needle bar and saidlooper shaft.

2. In a zig-zag stitch forming sewing machine comprising a base; asubstantially L-shaped hollow machine body having a longer horizontallyextending body portion and a relatively shorter vertically extendingbody portion, the combination of a looper shaft mounted in said basereciprocably in a horizontal direction parallel to the longer bodyportion of said L-shaped machine body; a needle bar slidably mounted forvertical movement at the free end of said horizontally extending longerbody portion of said L-shaped machine body; a substantially elongatedbail having a longer bail portion and a relatively shorter bail portion,said bail being so disposed within said machine body that said longerbail portion is located within said longer body portion and said shorterbail portion is located within said short body portion and dependinginto said base; means including an enlarged free end portion upon thelonger bail portion for supporting the needle bar for vertical slidingmovement, the short end of said bail having a bearing hole through whichthe looper shaft extends means upon said looper shaft engaging with saidbail at both ends of the bearing hole therein for preventing aXialdisplacement of said looper shaft with respect to said bail; and meansfor reciprocating said L-shaped bail in a horizontal direction andthereby oscillating the bail together with said needle bar and saidlooper shaft.

3. In a zig-zag stitch forming. sewing machine comprising a base; amachine body on said base; a horizontal looper shaft mounted in saidbase for reciprocation in a horizontal direction, the combination of aneedle bar arranged partly within the machine body and depending towardsaid base; an elongated bail located within said machine body having anintegral depending portion projecting into said base and mounted forhorizontal reciprocation; an enlarged end portion uponthe elongated bailin which the needle bar is slidably mounted for vertical movement, thedepending portion of said bail having a bearing hole for supporting saidlooper shaft in order to allow the latter to extend through said bail;means upon said looper shaft engaging with said bail at both ends of thebearing hole therein for preventing axial displacement of said loopershaft with respect to said bail; and operating means for reciprocatingsaid bail in the horizontal direction and thereby oscillating the bailtogether with said needle bar and said looper shaft; said operatingmeans including an arm disposed transversely of the depending portion ofsaid bail; an angularly adjustable guide member; a crank with aconnecting rod pivotally connected to the intermediate portion of saidarm and the latter arm at the ends thereof being respectively pivotallyconnected to said bail and operatively in contact with said angularlyadjustable guide member, the guide member having guide means of suchconstruction for guiding said arm that horizontal movements aretransferred to said arm and to the bail upon rotation of said crank.

4. In a zig-zag stitch forming sewing machine comprising a base; amachine body on said base; a horizontal looper shaft mounted on saidbase for reciprocation in horizontal direction, the combination of aneedle bar arranged partly within the machine body and depending towardsaid base; an elongated bail located within said machine body having anintegral depending portion projecting 'into said base and mounted forhorizontal reciprocation; an enlarged end portion upon the elongatedbail in which the needle bar is slidably mounted for vertical movement,the depending portion of said bail having a bearing hole for supportingsaid looper shaft in order to allow the latter to extend through saidbail; means upon /said looper shaft engaging With said bail at both endsof the bearing hole therein for preventing axial displacement of saidlooper shaft with respect to said bail and operating means forreciprocating said bail in the horizontal direction and therebyoscillating the bail together with said needle bar and said loopershaft; said operating means including an arm disposed transversely ofthe depending portion of said bail; an angularly adjustable guidemember; a crank With a connecting rod pivotally connected to theintermediate portion of said arm and the latter arm at one end thereofoperatively engaging with said bail, the angularly adjustable guidemember having a curvilinear cam groove; and a follower rotatably mountedat the other end of said arm and engagin-g in said curvilinear camgroove, at least the major intermediate portion of the curvilinear camgroove having a radius substantially equal to the length of said arm.

5. In a zig-zag stitch-forming sewing machine comprising a base; amachine body on said base; and a horizontal looper shaft mounted onsaidbase for reciprocation in horizontal direction, the combination of aneedle bar arranged partly Within the machine body and depending towardsaid base; an elongated bail located Within said machine body having anintegral depending portion projecting into said base and mounted forhorizontal reciprocation; an enlarged end portion upon the elongatedbail in which the needle bar is slidably mounted for vertical movement,the depending portion of said bail having a bearing hole for supportingsaid looper shaft in order to allow the latter to extend through saidbail;

means upon said looper shaft engaging with said bail at both ends of thebearing hole therein for preventing axial displacement of said loopershaft with respect to said bail; and operating means for reciprocatingsaid bail in horizontal direction and thereby oscillating the bailtogether With said needle bar and said looper shaft, said operatingmeans including an arm disposed transversely of the depending portion ofsaid bail; an'angularly adjustable guide member, a crank with aconnecting rod pivotally connected to the intermediate portion of saidarm and the latter arm at one end thereof operatively engaging with saidbail, the angularly adjustable guide member having a curvilinear camgroove; a follower roller rotatably mounted at the other end of said armand engaging in said curvilinear cam groove, at least the majorintermediate portion of the curvilinear cam groove having a radiussubstantially equal to the length of said arm; a rotatably adjustablesleeve mounted in said machine body and having an eccentric bearing holetherein; and a shaft rotatably mounted in the eccentric bearing hole insaid rotatably adjustable sleeve and rigidly secured at one end thereofto said guide member.

ARNLJOT AUSTLID.

REFERENCES CITED The following references are vof record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,232,263 Finch July 3, 19172,045,340 Bolter June 23, 1936 FOREIGN PATENTS Number Country Date421,357 Germany Nov. 10, 1925

